Calculator
IQ percentile calculator
Enter an IQ score to see what share of people you outscore, or enter a percentile to find the matching IQ.
An IQ of 120 is the
91th percentile
Higher than 91% of people · about 1 person in 11 scores this high · Very high (superior)
IQ to percentile table
| IQ (SD 15) | Percentile |
|---|---|
| 80 | 9 |
| 90 | 25 |
| 100 | 50 |
| 110 | 75 |
| 115 | 84 |
| 120 | 91 |
| 125 | 95 |
| 130 | 98 |
| 135 | 99.0 |
| 145 | 99.9 |
How the calculation works
IQ scores follow a normal distribution. The calculator turns your score into a z-score, z = (IQ − 100) ÷ standard deviation, then reads the exact share of the curve below that point. Percentile to IQ runs the same step in reverse.
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How do I convert an IQ score to a percentile?
Subtract 100, divide by the standard deviation (usually 15) and look the result up on the normal curve. An IQ of 115 is one standard deviation above average, which is the 84th percentile. The calculator above does it exactly.
What percentile is an IQ of 130?
An IQ of 130 is the 98th percentile on a standard-deviation-15 test: higher than about 97.7% of people, or one person in 44.
What IQ is the 99th percentile?
The 99th percentile is an IQ of about 135 on a standard-deviation-15 test.
What IQ is the 90th percentile?
The 90th percentile is an IQ of about 119.
Why does my test use a different standard deviation?
Most modern tests (Wechsler, Stanford-Binet 5) use 15. Older Stanford-Binet editions used 16 and the Cattell scale uses 24. Pick the matching setting so the percentile is right.
Scores on this page use the modern IQ scale: average 100, standard deviation 15 (Wechsler, Stanford-Binet 5). Online tests give estimates; only a supervised test by a qualified psychologist yields a diagnostic score.